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The use of ise or ize endings in British English

Posted on 31st March 2014

Whenever I start a new project, I usually ask the client if they want US or British English and if the latter, do they want -ise or -ize endings. Recently though, it's become clear that many people don't realise that it's just as standard in British English to write organize as it is to write organise.

I'm not going to go into the detailed history of this (though the Oxford Dictionary Blog summarises it) nor am I going to say what is better or worse for any individual client. What I will do though is make sure that my clients are aware of their options so they can make the decisions they feel best suit them.

As the Oxford Dictionary blog says, and my colleagues and I repeat on a daily basis, consistency is key: make a choice whether to be organised or organized and stick with it.

Needless to say, the British English version has its exceptions though where even if you have -ize endings in most instances, the following take -ise:

  • advertise
  • advise
  • chastise
  • comprise
  • compromise
  • despise
  • devise
  • disguise
  • excise
  • exercise
  • improvise
  • incise
  • prise (not to be confused with prize)
  • revise
  • supervise
  • surmise
  • surprise
  • televise

Furthermore, there are some -yse verbs in British English that can't be written as -yze, such as analyse and paralyse.

The difference is clear in the dictionary: if it's an option, underneath the main version it will say "also", e.g. organize (also organise), or if it's a matter of right/wrong it will say what the US version is separately e.g. analyse (US analyze).

Ultimately, if you have a preference and don't have to conform to someone else's style guide, go with what you're comfortable with and what will be easiest to stick to.

Written by Kate Haigh.